本文利用同步辐射真空紫外和超声分子束反射式飞行时间质谱系统研究间二甲苯的光电离和离解光电离.通过测定母体离子C_(8)H_(10)^(+)和主要碎片离子(C_(8)H_(9)^(+)和C_(7)H_(7)^(+))的光电离效率谱,确定了母体分子的电离能和主要碎片离...本文利用同步辐射真空紫外和超声分子束反射式飞行时间质谱系统研究间二甲苯的光电离和离解光电离.通过测定母体离子C_(8)H_(10)^(+)和主要碎片离子(C_(8)H_(9)^(+)和C_(7)H_(7)^(+))的光电离效率谱,确定了母体分子的电离能和主要碎片离子(C_(8)H_(8)^(+)和C_(7)H_(7)^(+))的出现势分别为8.60±0.03 eV,11.76±0.04 eV和11.85±0.05 eV eV.在B3LYP/6-311++G(d,p)水平上优化了两个主要解离通道的反应物、过渡态、中间体和产物的结构,并在G3水平上计算了它们的能量,以及两个主要的离解光电离通道产物C_(7)H_(7)^(+)+CH_(3)和C_(8)H_(9)^(+)+H的能量.结合理论和实验结果,间二甲苯的离解光电离机理主要过程是C-H键或C-C键的离解和氢迁移.展开更多
The design of aircraft hydraulic pipeline system is limited by many factors,such as the integrity of aviation structure or narrow installation space,so the limited clamp support position should be considered.This pape...The design of aircraft hydraulic pipeline system is limited by many factors,such as the integrity of aviation structure or narrow installation space,so the limited clamp support position should be considered.This paper studied the frequency adjustment and dynamic responses reduction of the multi-support pipeline system through experiment and numerical simulation.To avoid the resonance of pipeline system,we proposed two different optimization programs,one was to avoid aero-engine working range,and another was to avoid aircraft hydraulic pump pulsation range.An optimization method was introduced in this paper to obtain the optimal clamp position.The experiments were introduced to validate the optimization results,and the theoretical optimization results can agree well with the test.With regard to avoiding the aero-engine vibration frequency,the test results revealed that the first natural frequency was far from the aero-engine vibration frequency.And the dynamic frequency sweep results showed that no resonance occurred on the pipeline in the engine vibration frequency range after optimization.Additionally,with regard to avoiding the pump vibration frequency,the test results revealed that natural frequencies have been adjusted and far from the pump vibration frequency.And the dynamic frequency sweep results showed that pipeline under optimal clamp position cannot lead to resonance.The sensitivity analysis results revealed the changing relationships between different clamp position and natural frequency.This study can provide helpful guidance on the analysis and design of practical aircraft pipeline.展开更多
OBJECTIVE To screen metastatic-related genes in human gastric cancer by a low-density cDNA microarray technique. METHODS A total of 18 paired gastric cancer and adjacent normal mu-cosa were examined by a low-density c...OBJECTIVE To screen metastatic-related genes in human gastric cancer by a low-density cDNA microarray technique. METHODS A total of 18 paired gastric cancer and adjacent normal mu-cosa were examined by a low-density cDNA microarray containing 23 genes. RT-PCR was used for further verification. RESULTS The mRNA expression of MMP -7, heparanase, S100A4, hTERT, hRad17 in gastric cancers was higher than that in coupled normal mucosa (P=0.002, 0.00011, 0.000072, 0.002, 0.00016 respectively), whereas nm23H1, and CDH1 were lower (P=0.003, 0.012 respectively). The concordance was verified further by RT-PCR with a correlation coefficient of 0.774. In gastric primary lesions the mRNA expression of MMP-7, heparanase and S100A4 was higher in the serosa involved compared to non-involved (P=0.003, 0.009, 0.012 respectively), whereas nm23H1, CDH1, KAI1 were lower (P=0.001, 0.001, 0.006 respectively). With respect to the area of serosa involvement, MMP-7 and heparanase expressions were higher in an area of more than 20 cm2 compared to an area of less than 20 cm2 (P=0.001, 0.02 respectively), whereas nm23H1, CDH1 and KAI1 were lower (P=0.030, 0.041, 0.031 respectively). MMP-7 and hTERT expressions were higher in the heavier lymph node metastatic cases (no less than 7) than in the lighter lymph node metastatic cases (no more than 6, P=0.001, 0.005 respectively). CONCLUSION Expression of MMP -7, S100A4, heparanase, hTERT, KAI1, CDH1 and nm23H1 correlated closely with invasion and metastasis in gastric carcinomas. The low-density cDNA microarrays can be used to examine the expression of many genes simultaneously, parallely and quickly.展开更多
Precise control of machining deformation is crucial for improving the manufacturing quality of structural aerospace components.In the machining process,different batches of blanks have different residual stress distri...Precise control of machining deformation is crucial for improving the manufacturing quality of structural aerospace components.In the machining process,different batches of blanks have different residual stress distributions,which pose a significant challenge to machining deformation control.In this study,a reinforcement learning method for machining deformation control based on a meta-invariant feature space was developed.The proposed method uses a reinforcement-learning model to dynamically control the machining process by monitoring the deformation force.Moreover,combined with a meta-invariant feature space,the proposed method learns the internal relationship of the deformation control approaches under different stress distributions to achieve the machining deformation control of different batches of blanks.Finally,the experimental results show that the proposed method achieves better deformation control than the two existing benchmarking methods.展开更多
Covalent organic frameworks(COFs)are a new kind of crystalline porous materials composed of organic molecules connected by covalent bonds,processes the characteristics of low density,large specific surface area,adjust...Covalent organic frameworks(COFs)are a new kind of crystalline porous materials composed of organic molecules connected by covalent bonds,processes the characteristics of low density,large specific surface area,adjustable pore size and structure,and easy to functionalize,which have been widely used in the field of membrane separation technology.Recently,there are more and more researches focusing on the preparation methods,separation application,and mechanism of COF membranes,which need to be further summarized and compared.In this review,we primarily summarized several conventional preparation methods,such as two-phase interfacial polymerization,in-situ growth on substrate,unidirectional diffusion method,layer-by-layer assembly method,mixed matrix membranes,and so on.The advantages and disadvantages of each method are briefly summarized.The application potential of COF membrane in liquid separation are introduced from four aspects:dyeing wastewater treatment,heavy metal removal,seawater desalination and oil-water separation.Then,the mechanisms including pore structure,hydrophilic/hydrophobic,electrostatic repulsion/attraction and Donnan effect are introduced.For the efficient removal of different kind of pollutions,researchers can select different ligands to construct membranes with specific pore size,hydrophily,salt or organic rejection ability and functional group.The ideas for the design and preparation of COF membranes are introduced.Finally,the future direction and challenges of the next generation of COF membranes in the field of separation are prospected.展开更多
Organic field-effect transistors(OFETs)refer to field-effect transistors that use organic semiconductors as channel materials.Owing to the advantages of organic materials such as solution processability and intrinsic ...Organic field-effect transistors(OFETs)refer to field-effect transistors that use organic semiconductors as channel materials.Owing to the advantages of organic materials such as solution processability and intrinsic flexibility,OFETs are expected to be applicable in emergent technologies including wearable electronics and sensors,flexible displays,internet-of-things,neuromorphic computing,etc.Improving the electrical performance and developing multifunctionalities of OFETs are two major and closely relevant aspects for OFETs-related research.The former one aims for investigating the device physics and expanding the horizons of OFETs,while the later one is critical for leading OFETs into practical and emergent applications.The development in each of the two aspects would undoubtfully promote the other and bring more confidence for future development of OFETs.Hence,this review is divided into two parts that respectively summarize the recent progress in high-performance OFETs and multifunctional OFETs.展开更多
Xenon and krypton are widespread useful noble gases in commercial lighting, lasers, electronics, and medical industry. At the same time, radioactive noble gases may proliferate from used nuclear fuel and diffuse in op...Xenon and krypton are widespread useful noble gases in commercial lighting, lasers, electronics, and medical industry. At the same time, radioactive noble gases may proliferate from used nuclear fuel and diffuse in open atmospheres. Metal organic frameworks as hotspot porous materials for gases uptake and separation are considered to be potential solutions. In this review, we comprehensively summarized recent researches on metal organic frameworks for selective capture and separation of xenon and krypton. Particularly, we followed the aspects of different optimal design strategies, including optimal pore/cage size and geometry, open metal sites, ions (anions and cations), and polar functional groups for enhancing the xenon adsorption and separation performances. Meanwhile, a comparison of each strategy and the mechanisms of xenon/krypton separation were pointed out. The separation of krypton from gases mixtures by dual-bed systems was further discussed. Finally, some existing challenges and opportunities for possible real applications were proclaimed.展开更多
The catalytic ozonation treatment of secondary biochemical effluent for papermaking wastewater by Ag-doped nickel ferrite was investigated.Ag-doped catalysts prepared by sol-gel method were characterized,illustrating ...The catalytic ozonation treatment of secondary biochemical effluent for papermaking wastewater by Ag-doped nickel ferrite was investigated.Ag-doped catalysts prepared by sol-gel method were characterized,illustrating that Ag entirely entered the crystalline of Ni Fe2O4 and changed the surface properties.The addition of catalyst enhanced the removal efficiency of chemical oxygen demand and total organic carbon.The results of gas chromatography-mass spectrometer,ultraviolet light absorbance at 254 nm and threedimensional fluorescence excitation-emission matrix suggested that aromatic compounds were efficiently degraded and toxic substances,such as dibutyl phthalate.In addition,the radical scavenging experiments confirmed the hydroxyl radicals acted as the main reactive oxygen species and the surface properties of catalysts played an important role in the reaction.Overall,this work validated potential applications of Ag-doped Ni Fe2O4 catalyzed ozonation process of biologically recalcitrant wastewater.展开更多
Background:Although colorectal oligometastases to the liver can potentially be cured with aggressive local abla-tion,the efficacy of adjuvant chemotherapy(ACT)for such metastasis remains unclear.The present study expl...Background:Although colorectal oligometastases to the liver can potentially be cured with aggressive local abla-tion,the efficacy of adjuvant chemotherapy(ACT)for such metastasis remains unclear.The present study explored the effects of ACT on patients with colorectal liver oligometastases(CLO)after curative resections and aimed to iden-tify patients who could benefit from ACT.Methods:We retrospectively analyzed 264 eligible patients with CLO who underwent curative resection between September 1999 and June 2015.Recurrence-free survival(RFS)and overall survival(OS)were analyzed using the Kaplan-Meier method and log-rank test;prognostic factors were a by Cox regression modeling.Results:Among 264 patients,200(75.8%)patients received ACT and 64(24.2%)did not receive ACT.These two groups did not significantly differ in clinicopathologic characteristics,and had comparable 3-year OS and RFS rates(RFS:42.1%vs.45.7%,P=0.588;OS:69.7%vs.62.7%,P=0.446)over a median follow-up duration of 35.5 months,irrespective of preoperative chemotherapy.ACT markedly improved 3-year OS in high-risk patients with Memorial Sloan-Kettering Cancer Center clinical risk scores(MSKCC-CRS)of 3-5(68.2%vs.33.8%,P=0.015),but presented no additional benefit in patients with MSKCC-CRS of 0-2(72.2%vs.78.6%,P=0.834).In multivariate analysis,ACT was independently associated with improved OS in patients with MSKCC-CRS of 3-5.Conclusions:ACT might offer a prognostic benefit in high-risk patients with CLOs after curative liver resection,but not in low-risk patients.Therefore,patients’risk status should be determined before ACT administration to optimize postoperative therapeutic strategies.展开更多
The third-order nonlinear optical(NLO)materials with stimuli-responsive properties have received extraordinary attention due to their controllable photophysical properties.In this work,two attractive metal complexes t...The third-order nonlinear optical(NLO)materials with stimuli-responsive properties have received extraordinary attention due to their controllable photophysical properties.In this work,two attractive metal complexes third-order NLO switches,which are far superior to congeneric optical switches in terms of their performance conversion,versatility,and fast response,were successfully designed and synthesized.The test of their third-order NLO properties proves that the metal complexes exhibit reverse saturable absorption and self-defocusing refraction.After light irradiation,the third-order NLO behavior turns quickly into self-focusing refraction.The relation between the molecular structures and the third-order NLO properties was investigated via1H nuclear magnetic resonance and ultraviolet-visible absorption.The results show that the metal ions have a significant influence on the NLO behavior and reveal the origin of third-order NLO properties via Z-scan determinations,pump-probe technology,and density functional theory calculations.These metal complexes can be used as third-order NLO switches with excellent fatigue resistance and broaden the application range of third-order NLO materials with adjustable performances.展开更多
As the water drive reservoir enters extra high water cut stage(greater than 80%),remaining oil distribution becomes increasingly dispersed.Research on micro residual oil in pore appears particularly important for rese...As the water drive reservoir enters extra high water cut stage(greater than 80%),remaining oil distribution becomes increasingly dispersed.Research on micro residual oil in pore appears particularly important for reservoir development at extra high water cut stage.Oil occurrence characteristics recognition helps to understand the distribution of remaining oil and the mechanical characteristics of oil is the guide for tapping the remaining oil.On the basis of pore scale oil ewater two phase flow experiments,micro distribution of remaining oil is divided into four occurrence states in accordance with oil features at different stage of water flooding,the flake of remaining oil,oil column,oil droplet and oil film.A quantitative characterization method of remaining oil occurrence states is established.By using micro numerical simulation method,change rules of four occurrence states of remaining oil during the process of water displacement and the mechanical characteristics of different occurrence state of remaining oil are analyzed.Results show that the continuous oil phase gradually transforms to discontinuous phase and even to dispersed phases during the water flooding process.At extra high water cut stage,most of remaining oil are dispersed oil columns,oil droplets and oil films,which are the main target of remaining oil to be tapped.By changing water flow direction or increasing the displacement pressure gradient,the surface adsorption force acting on oil columns are overcome,and then the oil columns begin to move and finally to be produced out.Oil droplets in pore-throat center are scoured and carried out by water as the increase of the injection volume,while the oil droplets in blind ends and the oil films are extracted out by adding chemicals to reduce the interfacial tension,so as to enhance oil recovery.For water flooding reservoir,the corresponding tapping measures for four types of oil occurrence states brought forward have great meanings of improving reservoir recovery at high water cut stage.展开更多
Flooding events tend to destroy the original flood-intolerant vegetation in riparian zones,but the flood-tolerant species can confront the stress,and contribute to the riparian ecosystem.Grass species,Hemarthria altis...Flooding events tend to destroy the original flood-intolerant vegetation in riparian zones,but the flood-tolerant species can confront the stress,and contribute to the riparian ecosystem.Grass species,Hemarthria altissima,are usually dominant in the riparian zones.This species is considered as good forage which is usually grazed by livestock or mowed by local people.Therefore,the apical tissues of the plants are often removed,and the plants have to grow without stem apexes,during their life cycle.In this study,we aimed to examine the differences in growth performance of intact versus apex-cut individuals of H.altissima upon complete submergence.Two groups of H.altissima plants(with and without shoot apexes)were treated with dark non-submergence and dark complete submergence conditions for 200 days.During the experiment,we measured plant growth,biomass changes in plant organs,and the consumption of non-structural carbohydrates(NSC)by different tissues.During submergence,shoot elongation stopped,and around six lateral buds were developed averagely by each plant without apexes.This growth performance finally caused 60%decline of NSC in underground parts.The relatively intensive consumption of carbohydrates in submerged apex-removed plants induced the 21%stem length decreased under water,which indicated the decreasing submergence tolerance of plants with shoot apex removed.Therefore,we suggest that when using H.altissima for restoring degraded riparian ecosystems,the shoot apexes should be protected from grazing by livestock or harvesting by local people in order to maintain the submergence tolerance of H.altissima.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.11275006,No.12105042,No.11805032,No.11505027,No.11575178,No.U1532137)Nuclear Technology Application Engineering Research Center Open Foundation of Ministry of Education(No.HJSJYB2015-6,No.HJSJYB2017-1,HJSJYB2018-6)+4 种基金the Chinese Scholarship Council(No.201608360053)the Graduate Students High-Quality Course Construction Program of Jiangxi Province(No.JXYYK2016-12)the China Postdoctoral Science Foundation(No.2013M531530)the Doctoral Foundation of East China University of Technology(No.DHBK201401,No.DHBK2018059)the Provincial Natural Science Research Program of Higher Education Institutions of Anhui Province(No.KJ2012B086).
文摘本文利用同步辐射真空紫外和超声分子束反射式飞行时间质谱系统研究间二甲苯的光电离和离解光电离.通过测定母体离子C_(8)H_(10)^(+)和主要碎片离子(C_(8)H_(9)^(+)和C_(7)H_(7)^(+))的光电离效率谱,确定了母体分子的电离能和主要碎片离子(C_(8)H_(8)^(+)和C_(7)H_(7)^(+))的出现势分别为8.60±0.03 eV,11.76±0.04 eV和11.85±0.05 eV eV.在B3LYP/6-311++G(d,p)水平上优化了两个主要解离通道的反应物、过渡态、中间体和产物的结构,并在G3水平上计算了它们的能量,以及两个主要的离解光电离通道产物C_(7)H_(7)^(+)+CH_(3)和C_(8)H_(9)^(+)+H的能量.结合理论和实验结果,间二甲苯的离解光电离机理主要过程是C-H键或C-C键的离解和氢迁移.
基金Supported by National Natural Science Foundation of China(Grant No.51875460)Aviation Power Foundation(Grant No.6141B090320)Foundation of Innovation and Creation for Graduate Students in Northwestern Ploytechnical University(Grant No.ZZ2019124).
文摘The design of aircraft hydraulic pipeline system is limited by many factors,such as the integrity of aviation structure or narrow installation space,so the limited clamp support position should be considered.This paper studied the frequency adjustment and dynamic responses reduction of the multi-support pipeline system through experiment and numerical simulation.To avoid the resonance of pipeline system,we proposed two different optimization programs,one was to avoid aero-engine working range,and another was to avoid aircraft hydraulic pump pulsation range.An optimization method was introduced in this paper to obtain the optimal clamp position.The experiments were introduced to validate the optimization results,and the theoretical optimization results can agree well with the test.With regard to avoiding the aero-engine vibration frequency,the test results revealed that the first natural frequency was far from the aero-engine vibration frequency.And the dynamic frequency sweep results showed that no resonance occurred on the pipeline in the engine vibration frequency range after optimization.Additionally,with regard to avoiding the pump vibration frequency,the test results revealed that natural frequencies have been adjusted and far from the pump vibration frequency.And the dynamic frequency sweep results showed that pipeline under optimal clamp position cannot lead to resonance.The sensitivity analysis results revealed the changing relationships between different clamp position and natural frequency.This study can provide helpful guidance on the analysis and design of practical aircraft pipeline.
基金This work was supported by the Natural Science Foundation of Liaoning Province (No. 20022069).
文摘OBJECTIVE To screen metastatic-related genes in human gastric cancer by a low-density cDNA microarray technique. METHODS A total of 18 paired gastric cancer and adjacent normal mu-cosa were examined by a low-density cDNA microarray containing 23 genes. RT-PCR was used for further verification. RESULTS The mRNA expression of MMP -7, heparanase, S100A4, hTERT, hRad17 in gastric cancers was higher than that in coupled normal mucosa (P=0.002, 0.00011, 0.000072, 0.002, 0.00016 respectively), whereas nm23H1, and CDH1 were lower (P=0.003, 0.012 respectively). The concordance was verified further by RT-PCR with a correlation coefficient of 0.774. In gastric primary lesions the mRNA expression of MMP-7, heparanase and S100A4 was higher in the serosa involved compared to non-involved (P=0.003, 0.009, 0.012 respectively), whereas nm23H1, CDH1, KAI1 were lower (P=0.001, 0.001, 0.006 respectively). With respect to the area of serosa involvement, MMP-7 and heparanase expressions were higher in an area of more than 20 cm2 compared to an area of less than 20 cm2 (P=0.001, 0.02 respectively), whereas nm23H1, CDH1 and KAI1 were lower (P=0.030, 0.041, 0.031 respectively). MMP-7 and hTERT expressions were higher in the heavier lymph node metastatic cases (no less than 7) than in the lighter lymph node metastatic cases (no more than 6, P=0.001, 0.005 respectively). CONCLUSION Expression of MMP -7, S100A4, heparanase, hTERT, KAI1, CDH1 and nm23H1 correlated closely with invasion and metastasis in gastric carcinomas. The low-density cDNA microarrays can be used to examine the expression of many genes simultaneously, parallely and quickly.
基金This work is supported by National Key R&D Programs of China,No.2021YFB3301302the National Natural Science Foundation of China,No.52175467the National Science Fund of China for Distinguished Young Scholars,No.51925505。
文摘Precise control of machining deformation is crucial for improving the manufacturing quality of structural aerospace components.In the machining process,different batches of blanks have different residual stress distributions,which pose a significant challenge to machining deformation control.In this study,a reinforcement learning method for machining deformation control based on a meta-invariant feature space was developed.The proposed method uses a reinforcement-learning model to dynamically control the machining process by monitoring the deformation force.Moreover,combined with a meta-invariant feature space,the proposed method learns the internal relationship of the deformation control approaches under different stress distributions to achieve the machining deformation control of different batches of blanks.Finally,the experimental results show that the proposed method achieves better deformation control than the two existing benchmarking methods.
基金funding support from the National Science Foundation of China(Nos.22276054,U2167218,22006036)the Beijing Outstanding Young Scientist Program(HY,ZC,XW)。
文摘Covalent organic frameworks(COFs)are a new kind of crystalline porous materials composed of organic molecules connected by covalent bonds,processes the characteristics of low density,large specific surface area,adjustable pore size and structure,and easy to functionalize,which have been widely used in the field of membrane separation technology.Recently,there are more and more researches focusing on the preparation methods,separation application,and mechanism of COF membranes,which need to be further summarized and compared.In this review,we primarily summarized several conventional preparation methods,such as two-phase interfacial polymerization,in-situ growth on substrate,unidirectional diffusion method,layer-by-layer assembly method,mixed matrix membranes,and so on.The advantages and disadvantages of each method are briefly summarized.The application potential of COF membrane in liquid separation are introduced from four aspects:dyeing wastewater treatment,heavy metal removal,seawater desalination and oil-water separation.Then,the mechanisms including pore structure,hydrophilic/hydrophobic,electrostatic repulsion/attraction and Donnan effect are introduced.For the efficient removal of different kind of pollutions,researchers can select different ligands to construct membranes with specific pore size,hydrophily,salt or organic rejection ability and functional group.The ideas for the design and preparation of COF membranes are introduced.Finally,the future direction and challenges of the next generation of COF membranes in the field of separation are prospected.
基金supported by the National Key Research and Development Program of China(Nos.2019YFE0116700 and 2019YFA0705900)Ministry of Science and Technology,National Natural Science Foundation of China(Nos.62075224,22021002,51873182 and 52103231)+3 种基金Zhejiang Province Science and Technology Plan(No.2021C04012)Zhejiang Provincial Department of Science and Technologysupported by the Lu Jiaxi International Teams Project(No.GJTD-2020–02)the Fundamental Research Funds for the Central Universities(No.2021QNA4033)。
文摘Organic field-effect transistors(OFETs)refer to field-effect transistors that use organic semiconductors as channel materials.Owing to the advantages of organic materials such as solution processability and intrinsic flexibility,OFETs are expected to be applicable in emergent technologies including wearable electronics and sensors,flexible displays,internet-of-things,neuromorphic computing,etc.Improving the electrical performance and developing multifunctionalities of OFETs are two major and closely relevant aspects for OFETs-related research.The former one aims for investigating the device physics and expanding the horizons of OFETs,while the later one is critical for leading OFETs into practical and emergent applications.The development in each of the two aspects would undoubtfully promote the other and bring more confidence for future development of OFETs.Hence,this review is divided into two parts that respectively summarize the recent progress in high-performance OFETs and multifunctional OFETs.
基金funding support from the National Science Foundation of China(Grants Nos.22276054,U2167218,and 22006036)the Beijing Outstanding Young Scientist Program.
文摘Xenon and krypton are widespread useful noble gases in commercial lighting, lasers, electronics, and medical industry. At the same time, radioactive noble gases may proliferate from used nuclear fuel and diffuse in open atmospheres. Metal organic frameworks as hotspot porous materials for gases uptake and separation are considered to be potential solutions. In this review, we comprehensively summarized recent researches on metal organic frameworks for selective capture and separation of xenon and krypton. Particularly, we followed the aspects of different optimal design strategies, including optimal pore/cage size and geometry, open metal sites, ions (anions and cations), and polar functional groups for enhancing the xenon adsorption and separation performances. Meanwhile, a comparison of each strategy and the mechanisms of xenon/krypton separation were pointed out. The separation of krypton from gases mixtures by dual-bed systems was further discussed. Finally, some existing challenges and opportunities for possible real applications were proclaimed.
基金supported by National Key R&D Program of China(No.2018YFC0406300)the operation for central university of Hohai University(No.2013/B18020148)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘The catalytic ozonation treatment of secondary biochemical effluent for papermaking wastewater by Ag-doped nickel ferrite was investigated.Ag-doped catalysts prepared by sol-gel method were characterized,illustrating that Ag entirely entered the crystalline of Ni Fe2O4 and changed the surface properties.The addition of catalyst enhanced the removal efficiency of chemical oxygen demand and total organic carbon.The results of gas chromatography-mass spectrometer,ultraviolet light absorbance at 254 nm and threedimensional fluorescence excitation-emission matrix suggested that aromatic compounds were efficiently degraded and toxic substances,such as dibutyl phthalate.In addition,the radical scavenging experiments confirmed the hydroxyl radicals acted as the main reactive oxygen species and the surface properties of catalysts played an important role in the reaction.Overall,this work validated potential applications of Ag-doped Ni Fe2O4 catalyzed ozonation process of biologically recalcitrant wastewater.
基金funded by the National Natural Science Foundation of China(No.81772595)Sun Yat-sen University Clinical Research 5010 Program(2015024)+1 种基金Sun Yat-sen University Clinical Research 5010 Program(2013013)Science and Technology Planning Project of Guangdong Province(Grant No.2013B021800146).
文摘Background:Although colorectal oligometastases to the liver can potentially be cured with aggressive local abla-tion,the efficacy of adjuvant chemotherapy(ACT)for such metastasis remains unclear.The present study explored the effects of ACT on patients with colorectal liver oligometastases(CLO)after curative resections and aimed to iden-tify patients who could benefit from ACT.Methods:We retrospectively analyzed 264 eligible patients with CLO who underwent curative resection between September 1999 and June 2015.Recurrence-free survival(RFS)and overall survival(OS)were analyzed using the Kaplan-Meier method and log-rank test;prognostic factors were a by Cox regression modeling.Results:Among 264 patients,200(75.8%)patients received ACT and 64(24.2%)did not receive ACT.These two groups did not significantly differ in clinicopathologic characteristics,and had comparable 3-year OS and RFS rates(RFS:42.1%vs.45.7%,P=0.588;OS:69.7%vs.62.7%,P=0.446)over a median follow-up duration of 35.5 months,irrespective of preoperative chemotherapy.ACT markedly improved 3-year OS in high-risk patients with Memorial Sloan-Kettering Cancer Center clinical risk scores(MSKCC-CRS)of 3-5(68.2%vs.33.8%,P=0.015),but presented no additional benefit in patients with MSKCC-CRS of 0-2(72.2%vs.78.6%,P=0.834).In multivariate analysis,ACT was independently associated with improved OS in patients with MSKCC-CRS of 3-5.Conclusions:ACT might offer a prognostic benefit in high-risk patients with CLOs after curative liver resection,but not in low-risk patients.Therefore,patients’risk status should be determined before ACT administration to optimize postoperative therapeutic strategies.
基金the National Natural Science Foundation of China(21671174 and U1904172)the Zhongyuan Thousand Talents Project,the Natural Science Foundation of Henan Province(182300410008)the Open Foundation of Guangxi Key Laboratory of Processing for Nonferrous Metals and Featured Materials,Guangxi University(2019GXYSOF12).
文摘The third-order nonlinear optical(NLO)materials with stimuli-responsive properties have received extraordinary attention due to their controllable photophysical properties.In this work,two attractive metal complexes third-order NLO switches,which are far superior to congeneric optical switches in terms of their performance conversion,versatility,and fast response,were successfully designed and synthesized.The test of their third-order NLO properties proves that the metal complexes exhibit reverse saturable absorption and self-defocusing refraction.After light irradiation,the third-order NLO behavior turns quickly into self-focusing refraction.The relation between the molecular structures and the third-order NLO properties was investigated via1H nuclear magnetic resonance and ultraviolet-visible absorption.The results show that the metal ions have a significant influence on the NLO behavior and reveal the origin of third-order NLO properties via Z-scan determinations,pump-probe technology,and density functional theory calculations.These metal complexes can be used as third-order NLO switches with excellent fatigue resistance and broaden the application range of third-order NLO materials with adjustable performances.
基金This research was supported by SINOPEC Major Projects,(J08).
文摘As the water drive reservoir enters extra high water cut stage(greater than 80%),remaining oil distribution becomes increasingly dispersed.Research on micro residual oil in pore appears particularly important for reservoir development at extra high water cut stage.Oil occurrence characteristics recognition helps to understand the distribution of remaining oil and the mechanical characteristics of oil is the guide for tapping the remaining oil.On the basis of pore scale oil ewater two phase flow experiments,micro distribution of remaining oil is divided into four occurrence states in accordance with oil features at different stage of water flooding,the flake of remaining oil,oil column,oil droplet and oil film.A quantitative characterization method of remaining oil occurrence states is established.By using micro numerical simulation method,change rules of four occurrence states of remaining oil during the process of water displacement and the mechanical characteristics of different occurrence state of remaining oil are analyzed.Results show that the continuous oil phase gradually transforms to discontinuous phase and even to dispersed phases during the water flooding process.At extra high water cut stage,most of remaining oil are dispersed oil columns,oil droplets and oil films,which are the main target of remaining oil to be tapped.By changing water flow direction or increasing the displacement pressure gradient,the surface adsorption force acting on oil columns are overcome,and then the oil columns begin to move and finally to be produced out.Oil droplets in pore-throat center are scoured and carried out by water as the increase of the injection volume,while the oil droplets in blind ends and the oil films are extracted out by adding chemicals to reduce the interfacial tension,so as to enhance oil recovery.For water flooding reservoir,the corresponding tapping measures for four types of oil occurrence states brought forward have great meanings of improving reservoir recovery at high water cut stage.
基金supported by National Natural Science Foundation of China(grant numbers U22A20448,31800331,31400480,31770465)National Key R&D Program of China(grant number 2023YFF1305204)+2 种基金Chongqing Talents Program(grant number cstc2021ycjh-bgzxm0316)the Fundamental Research Funds for the Central Universities(grant number SWU-KT23001)Science Foundation of School of Life Sciences SWU(grant numbers 20212017050401,20212005393901).
文摘Flooding events tend to destroy the original flood-intolerant vegetation in riparian zones,but the flood-tolerant species can confront the stress,and contribute to the riparian ecosystem.Grass species,Hemarthria altissima,are usually dominant in the riparian zones.This species is considered as good forage which is usually grazed by livestock or mowed by local people.Therefore,the apical tissues of the plants are often removed,and the plants have to grow without stem apexes,during their life cycle.In this study,we aimed to examine the differences in growth performance of intact versus apex-cut individuals of H.altissima upon complete submergence.Two groups of H.altissima plants(with and without shoot apexes)were treated with dark non-submergence and dark complete submergence conditions for 200 days.During the experiment,we measured plant growth,biomass changes in plant organs,and the consumption of non-structural carbohydrates(NSC)by different tissues.During submergence,shoot elongation stopped,and around six lateral buds were developed averagely by each plant without apexes.This growth performance finally caused 60%decline of NSC in underground parts.The relatively intensive consumption of carbohydrates in submerged apex-removed plants induced the 21%stem length decreased under water,which indicated the decreasing submergence tolerance of plants with shoot apex removed.Therefore,we suggest that when using H.altissima for restoring degraded riparian ecosystems,the shoot apexes should be protected from grazing by livestock or harvesting by local people in order to maintain the submergence tolerance of H.altissima.
